Investigations on treatment of waste from pig fattening units up to a quality suitable for water course discharge

Abstract

Studies were carried out between 1973 and 1977 concerning the biological purification of liquid manure from animal production units, especially that from pig fattening units. Starting with tests for further biological purification of biologically pretreated manure, the studies were extended to the treatment of raw liquid manure. The results show that in pig production in the context of mass animal keeping the liquid manure produced can be purified in principle by a combined biological-chemical treatment to a standard such that it can be discharged to water courses. The necessary treatment plants must then be designed according to the criteria required for the wastewater. Because of the high costs this should be done only if no agricultural land is available to utilise effluent and sludge of a biological treatment as fertiliser.